The value of cytogenetics for the taxonomy and evolution of Leaf Beetles (Coleoptera, Chrysomelidae)

Abstract

The advantages and pitfalls of cytogenetics for the taxonomy and evolution of Leaf Beetles are discussed. Karyology may provide clues for distinguishing cryptic sibling species as demonstrated in Chrysolina aurichalcea and Casslda viridis. The phylogenetic value of karyotypes can only be substantiated on the grounds of three general rules extensive sampling to determine the most widespread karyotype or meioformula, the criterion of parsimony, and parallel evolution of other characters. A modal karyotype cannot be equalized a priori to the most primitive karyotype. Hence, for simple effects of sampling, in a few Leaf Beetle subfamilies only the ancestral karyotype can be reasonably assessed. The Chrysomelinae subfamily is studied in significantly greater detall, and the probable interrelationships of their higher taxa based on the chromosomal findings and their correlation with other characters of phylogenetic interest is discussed The presumed effects of deme size and specialized phytophagy on the karyological evolution of Chrysomelinae genera are also dealt with.